GPT and anemia (phenotype): As shown in Table 6 (step 3), after backward logistic regression, the independent risk factors for MTX-related grade 3/4 anemia included ALT ratio (OR: 1.367, 95% CI: 1.144–1.641, P = 0.001), TBIL (OR: 1.114, 95% CI: 1.062–1.172, P = 0.000), RBC (OR: 0.435, 95% CI: 0.276–0.678, P = 0.000), dose (OR: 2.359, 95% CI: 1.829–3.203, P = 0.000), and rs56103835 TT+TC (OR: 0.360, 95% CI: 0.239–0.541, P = 0.000).